Such a fuel supply system is known, for example, in connection with internal combustion engines having direct injection. There, the fuel in the storage chamber is made available under a high pressure. The pressure in the storage chamber is controlled to the desired setpoint value with the aid of the pressure-control valve. To inject the fuel into a combustion chamber of the internal combustion engine, an injection valve belonging to the combustion chamber is opened, and the injected fuel is then ignited with the aid of a spark plug. In internal combustion engines having direct injection, the injection valves are arranged in such a way that the fuel is not injected into an intake manifold or the like, but rather is injected directly into the combustion chambers.
The quantity of fuel to be injected is adjusted with the aid of the period of time the respective injection valve is open. At the same time, this period of time is a function of the pressure in the storage chamber. The greater the pressure, the shorter is the period of time for the injection of the same quantity of fuel. To take into account the pressure in the storage chamber when ascertaining the period of time for injecting, a pressure sensor which measures the actual value of the pressure in the storage chamber is allocated to the storage chamber.
If this pressure sensor is defective, thus if incorrect or no values at all are being measured by the pressure sensor, then, because of this, the period of time, and consequently the proportioning of the fuel quantity to be injected, is falsified.